When I was a kid I thought that Norman Ferguson and Tee He’s “Pinocchio” was not only the best movie I had seen but probably the best movie that will ever be made. Seventy-six years later, when I sit in on some allegedly more mature pictures, I am likely to think back to my judgement on that cartoon with fondness for its accuracy. I graduated from kiddie cartoons three years later when “Lassie Come Home” became my favorite picture of all time and began my admiration for the acting chops of Elizabeth Taylor. “Lassie Come Home” features a destitute family that has to sell its faithful collie, a dog which, having bonded with its original family, escapes from its new owner and treks from Scotland to its Yorkshire home. The term “faithful” does not begin to describe the intense feeling of a dog and its human partner. The dog-human bond is now explored with finesse and sentimentality by Gabriela Cowperthwaite, whose “Megan Leavey” recounts a true story in narrative terms and focuses on Kate Mara as the title character.

“Megan Leavey,” the story of a young woman and the dog she loves, has a PG-13 rating, which would make this a natural for the small fry, though given their limited experience in life they may assume that the only people who enter the service voluntarily do so because they have distressing home lives or cannot find a job that suits their ability. The title character, played by Kate Mara, is fired from her job entertaining kids because, her boss says, she does not have the ability to bond with people. At that point she has no idea that she’d be an ace bonding with a large, aggressive German Shepherd, but she finds out after enlisting in the Marines, following a serious argument with her mother Jackie Leavey (Edie Falco, who plays a different Jackie on TV) who is divorced from her father, Bob (Bradley Whitford). Jackie is not physically abusive but is simply fed up with a daughter who loafs around the house with nothing to do. Give Jackie credit for motivating her unfocused daughter to find herself.

In the Marines, she is assigned after urinating in public at the base to the K9 unit, washing down the dogs’ “business,” and feeling threatened by one particularly fierce Shepherd called Rex. With her new perseverance, she persuades her superior officer Gunnery Sergeant Massey (Common) to let her train Rex after the dog had inflicted a bad cut on the arm of her handler. She, the dog, and her fellow Marines go on missions in Iraq to find weapons and explosives, and Rex handles the job with aplomb, though not even this prize dog can find weapons of mass destruction. But when Rex is injured and retired from the force as certified “unadoptable,” Megan takes upon herself the project of getting the Marines to overturn their ruling, using the persuasive skills of her New York Senator Chuck Schumer to use his office for her benefit.

Some action is shown, including one scene in which an Iraqi citizen, thanking the Marines for “dealing with the insurgents,” is uncovered as a terrorist with an array of guns hidden behind some carpeting. Rex once again becomes a war hero and by extension his devoted trainer. But this is in no way the kind of war picture like “American Sniper,” a terrific action movie also based on a true story, and perhaps the lack of more explosive action results from its direction by a woman. (Cowperthwaite is best known for “Blackfish,” a documentary about people and whales, similarly a fine choice for parents and their kids.)

Before seeing “Megan Leavey,” I had assumed that women in the Marines are tough-as-nails, the sort you wouldn’t want to mess with. Given that this picture is based on the real-life hero who is petite (the real Megan Leavey is somewhat taller), with nary a smidgen of vulgarity—though she can go out and get drunk and be one of the guys. No sexual harassment is present in this man’s Marines, and the ending, oozing with sentiment, could have you in tears of joy. Kate Mara fill the role quite nicely, trekking with the crew to filming locations in Rome Georgia, Charleston South Carolina, and in Spain’s Cartagena, Mazarron and Zaragoza.